Magnetic antibacklash mechanism



Dec. 14, 1954 c. DE BRABANDER EX'AL 2,696,555

MAGNETIC ANTIBACKLASH MECHANISM Filed March 8, 1951 INVENTORS CAM/EL DEBRABANDER FRANK RUDBARG BY fiw fiw ATTORNEY.

MAGNETIC ANEIBACKLASH Camiellde' BrabandenflN'ewport,. lleltyandfrank Rudbarg,. jPhiladelpliia, 2a., assignors fto. American Viscose Cor- ,poration, Wilmington,j;Del., azcorporalion nfDelaware ApplicationMarchS, -195 1,*Serinl No."2 14;502

4 Claims. (Cl. 28-716) FFhepresent invention relates toimprovements: in spindle driving mechanisms, and i particularly, a to the elimination-of back lash resulting' fi om loosenessror play Within a mechanical drive system-tor transmitting torque'to the spindle. "Such "back-lash accelerates the weari'n a mechanical results in inferior performance of-the equipment being drivenas well' as products of inferior quality obtained from 'such rayon yarn, for example, the operation of god'et' gear boxes'without backflash or '-fiuttering'-' is greatly desired when spinning light denieryarn so-that thefrejshl'yspun filamentary material-maybe withdrawn from the=spinneret andistretched with as} little variationin denier=-as possible.

The present invention which involves *a magnetic" system forprod'ucing a light torque l'oad'or {drag load for oppos ingthe rotation-of gearspshafts', etc. and --obviously ,;has extensive potential applicability. For purposes of illustrationphowever, the invention is hereinbelow described with respect to yarn-handlinggodcts such "as used in the manufacturing of"viscoserayon yarn;

'It'is an object "of the presen'rin-vention' to provide a simple inexpensive drag-producingmec'hanismffor the elimination of'back-lashin rotative power ;tr ansmitti'ng systems. 'It' iszalso an object to utilize magnetic forces -power*transmission, and in many applications equipment. In the -manuf;actur ing of Y viscose to produce a drag load on rotatable-bodies; Still another-* object isito provi'cle a magnetic retarding structure whichmay "be readily installed on "existing power transmission svstemsrwithoutthenecessity for extensive modification. Other objects, features andladvantages will-be"- apparent from-the following description of the invention and the drawing relating thereto in;which "Fig. 1 is an elevation. partially in section of v a spindle drivingassembly in which the invention"is;incorporated;

*Fig.*2is-an end view of a magnetic mcmberof' theapparatus of Fig. 1;

Fig. 3 is a sectional view ofthe ma gnetic member;

Fig. 4 is a diagrammaticlinear development of the magnetic drag}, load system -gemployed -rirr the apparatus of Fig. 1;,

Fig. "5 'is an.,elevation drive illustrating --an alternative disposition of members; offra' magneticLdrag load system;

partially" in section of ,.a .worm.

. "Fig; 6':isiadiagrammaticview-of a .gear transmission I assembly inrwhichis incorporated a modified dragnload. s stern;

-Fi'g. 7 .is-ausectional'view'taken alongiline otFi'gv 6";:1and

Tn..accordance'with'the present invention, a dragt load may be imposed on a rotary member: supported byeanonrotatable member'to eliminateback-lash from a mechanical power transmitting 'system comprising "gears, sprockets and the like by securing one or more magnetic elements to either the rotary member or the support member in such a manner as to produce a series of spaced poles disposed in a circular pattern concentrically to the axis of rotation. The member to which magnetic elements are not attached supports a continuous band, annulus, or one or more non-continuous arcuate sections of magnetically-sensitive material concentric with, and adjacent to, the pole faces of the magnetic elements. The embodiments hereinafter described are merely illustrative of the arrangements possible.

Fig. 1 illustrates a spindle drive assembly such as is so spindle 4.

sand may beuscdl toposition the shaftZin-an -.sutface:=21. 'The housing a -normal "speed as.- the constant engagement and does not i add .t ..1..,..[ .n: ....s...,

' uscdtto :support ta= godetz-tlllrtbattmayibe incorporated: into. equipment: for .spinningv artificial :fllaments,-,=such as from:

.asealing elemcntvlfi prevents the: transfer of-Lliquidmaterial into or outz-ot therhousingd2. :Anothenshaft 'lJaeittends;

into, the "housing interlaced; zandttrans ersetrelationsh ip with respect'tmthe 1:1'. 'kotatiuewpowcriis-ttranrmitted gfromathe shaft 1'7 through -.a

worm :18?.'mounted :thereon'; in; mesh- .with .a wormtgearwu zsupportedohflhe shaft d-1.

:Aseshown, the housing al2r-has a recessv 20 i into which extends an, end portion of; the: shaft-1 1 i into engagement with-.a. set' scrcwz24' which serves-tas an .end thrust. hearing endwise. direo tion :within: the housing. ,sAniinner'flatysurfaceilsof the housing :isparallel 1 to theadjacent face of the gear, :19 and spaced therefrom sufficiently .toperinit; attachmcn" to the of an tannulanrnul'tiple pole .rnagnetictmembv -f22 hav'ing -.a plurality. of. axiallyaxtending and angularl spaced; permanently-magnetized ":bosses- Adjacent bosses -or projections Y 233- are mag netized with opposite polarity; The-shaftfllmaytbespositionedrendwisqwithin.

the 1 housing by: adjustment of the set :screw 24 :so that 1 the. magnetic: member 22 rrotatestwith clearance bet-ween iteandltheftlattsurfacedl. =-If-desired; howevergfrictional drageas well-gas magnetic: dragmay be utilized 'to: impose a dragload-onthe sp' lei-1'1 tandthe --member 22 in this: caseris I allowed to rotate I in engagement with gthe 12 ordinarily contains -a-- bath of lubricant-in which-the rotating: members are-at least partly submerged; thus exceasive wean or: abrasi'onbf 'slidably tengaged portions of the drag 'load members is avoided.

FigV- 4 illustrates-a linear development of the-member 22 and its relationship with the magnetically sensitive sec tion-of the housing-l 2 havingthe'g surface 2'1; 'I he;composition-of-magnetic forces whichproduce the drag force by which 1 backlash of the spindle 1 1 andthe 1=gbdet 1 I0 is eliminated is illustrated by the smalIarroWs.

The assembly shown in Fig. l is normally used-"in conjunction with another similar assembly (not shown) to forward and stretch ;a freshly spun 'Jyarn. "The godets rotate son spaced 'axes -'at different-per1pheral 1 speeds we so thatfthe-yarn, i'n passing from one godet to the morerapidlyrotating 'godet; is stretched. Backj-lash may-not occur to a" substantial degree 1 in the spinning- 0f heavy {denier yarns-but when handling light denier: yarns, the strength of the green yarn passing between: the godets is 'riot to prevent fiuttering oribaclt-lash. of' 0ne-or bothgodetsresulting'from play inthe ,-wor'm gear drives therefor; such as illustrated" -in' 'F-i'g. 1. When the speeds of one orbo'th of the godets -whi'ch forwarda. single yarn are "fluctuating in arange extending above and below result of back-lash, substantial dificrences' inthe stretching of progressivesectionsjof the yarn areebtained with corresponding variations in the. denier. A gdrag systemt in, accordance with: the present invention -=ma int ains teethiofi-the, gears in apprecia'bly to the power consumed in driving such godets. "If desired, a multiple pol'e member such as member of Figkl may-gbemounted on a surface whiclt is; fixedwitlrrespgct toQthe non-rotatable support memberas; shown in Fig. '5- wherein a magnetic dragmember 28, sirn '43 aifixed to the shaft and spindle respectively. A magnetic member 45 having permanently'magnetized radially outward extensions or teeth 46 is-secured to the driven Adjacent teeth 46 are improtsed with op- .Patented Dec. 14 l9 5fl a f mei b i v 3 posite polarity as indicated in Fig. 7. The member 45 rotates at close clearance with an annular member 48 of magnetically-sensitive material. Member 48 may be constructed with an inner diameter providing a minimum practical clearance with the teeth 46 and secured in place by a set screw 47. While member 48 is shown anchored within a housing surface 50 complementary to its exterior surface, the member 45 may be provided in a size suitable for rotating at close clearance with an annular surface of a magnetically-sensitive housing or magnetically-sensitive portion thereof disposed radially outwardly from, and concentrically with the member 45, thus eliminating the need for a separate'member.

Fig. 8 illustrates an alternative drag producing system wherein an exterior stationary annular member 53 is provided with permanently-magnetized teeth 54 which extend radially inwardly from the body of this member into close clearance with a ring-like member 56 of magnetically-sensitive material secured to a shaft 57. Magnetic forces are developed between members 53 and 56 in a manner similar to that illustratedin Fig. 4. If necessary, the member 53 may be positively anchored within a housing 58 by a set screw 59.

Permanently-magnetized members in. accordance with the present invention such as typified by member 22 of Figs. 1 to 4,

member 45 of Figs. 6 and 7, member 28 of Fig. and member 53 of Fig. 8 may be fabricated from a variety of metallic compositions familiar to those skilled in the forming of magnets. Such magnets are now obtainable in an unlimited variety of shapes and sizes and are commonly formed from alloys of-iron with other metals such as nickel, aluminum, copper, cobalt, man-' ganese, chromium, -and molybdenum by well-known sintering or casting procedures. Some of such alloy compositions may be found listed in Metals and Alloys Data Book (page 132), by S. L. Hoyt, published 1943. While the magnets herein described are shown as unitary in structure, magnets of the type which comprise an annular holder and a plurality of magnetic pole elements secured to the holder to provide a plurality of pole faces in a manner known to the art may also be used.

While preferred embodiments of the invention have been shown and described; it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.- I

We claim:

1. In spinning apparatus comprising a pair of godets, means for supporting the godets on fixed axes in spaced yarn-transferring relationship whereby one godet receives the yarn from the other, and means for driving the godets at different peripheral speeds, said first-mentioned godet being driven more rapidly to stretch the yarn passing thereto from the other godet; the combination with the godets and the driving means of a magnetic system for preventing back-lash in the transmission of power through the driving means comprising a permanently magnetized portion having spaced circularly disposed pole elements in concentric relationship with each axis and an arcuate magnetically-sensitive portion in opposed concentric relationship with said elements, adiacent ele-' ments-of said pole elements being opposite in polarity,

one -'of.each pair of the opposedportions of the magnetic system being held from rotation and the other portion of each pair being connected with a godet for rota tion therewith.-.

2. In spinning apparatus comprising a pair of godets, means for supporting the godets on fixed axes in spaced yarn-transferring relationship whereby one godet receives the yarn from the other, and means for driving the godets at' different peripheralspeeds, the first-mentioned godet being driven more rapidly to stretch the yarn passing thereto from the other godet; the combination with the 4 godets and the driving means of a magnetic system for preventing back-lash in the transmission of power through the driving means and the connection thereof with the godet comprising an annular magnet portion in concentric relationship with each axis, and an annular band portion of magnetically-sensitive material in concentric relationship with each magnet portion, said magnet portion having a plurality of pole elements spaced along a circumference thereof in opposed relationship to a circumference of the band portion, adjacent elements of said pole elements being opposite in polarity, and one of each pair of the opposed portions of the magnetic system being aflixed to the supporting means and the other portion of each pair being connected with a godet for rotation therewith.

3. In spinning apparatus comprising a pair of godets, a pair of shafts, each godet being mounted on one of the shafts, bearings for supporting the godets on fixed axes in spaced yarn-transferring relationship whereby one godet receives the yarn from the other, and means for driving the godets at different peripheral speeds, said first mentioned godet beingdriven more rapidly to stretch the yarn passing thereto from the other godet; the com- ""bination with the godets and the driving means of a 1' related shaft for rotation therewith and the other an lash of the godet'with respect to parts of said driving magnetic system for preventing back-lash in the trans- 1111581011 of power through the driving means and the connection thereof with the godets comprising two pairs ofannuli, each pair of annuli being supported conlcentrically with respect to a separate shaft, one annulus 30,

of each pair being a magnet having pole elements spaced along a circumference thereof and the other annulus being a band 'of magnetically-sensitive material, one annulus of each pair being associated with the coaxially nulus of the pair being mounted on the bearing associated with the first named annulus.

4. In spinning apparatus comprising a godet, means for supporting the godet on a fixed axis, means mounted i in spaced relationship with the godet for supplying yarn thereto at a predetermined rate, and means for driving the godet at a higher peripheral rate than said predetermined rate; in combination with the driving means and the godet, a magnetic system for preventing backmeans comprising a permanently magnetized portion having spaced circularly-disposed pole elements in concentric relation with an axis of rotation of said driving means, and an arcuate magnetically-sensitive portion in '-.opposed concentric relation with said elements, adiacent elements of said pole elements being opposite in polarity,

one of said opposed portions of the magnetic system being held from rotation and the other portion being connected in driving relation with the godet for rotation .altherewith.

References Cited in the file of this patent UNITED STATES PATENTS 'I Number Name Date 1,652,362 Joyce Dec. 13, 1927 1,870,000 Cunningham et a1 Aug. 2, 1932 2,129,529 Howard Sept. 6, 1938 2,255,420 Graham Sept. 9, 1941 2,257,300 Hines Sept. 30, 1941 2,293,748 Johnson .Aug.. 25, 1942 2,371,511 Faus Mar. 13, 1945 2,402,609 Brabander June 25, 1946 2,458,759 Abell Jan. 11, 1949 2,463,409 Moody Mar. 1, 1949 2,465,932 Romine Mar. 29, 1949 2,519,882 Bullard Aug. 22, 1950 2,550,861 Ransom May 1, 1951 

